JP7299347B2 - Pulsation of bristle drive - Google Patents

Description

FIELD OF THE DISCLOSURE The present disclosure relates generally to electric toothbrush systems, and more particularly to oscillating brush heads in synchronization with bristle rotation.

Typically, a power toothbrush has a toothbrush head, a toothbrush neck and a toothbrush handle. The brush head includes a movable bristle holder having a flat surface containing one or more bristle tufts. A motor in the toothbrush handle controls the movement of the bristle holder, moving the bristles up, down, left and right, such as in a circular motion pattern.

However, as the bristles move, the toothbrush head, neck, or handle may also vibrate, for example, through the hard plastic of the brush head or neck. These additional vibrations through the hard plastic can be annoying and uncomfortable for the user. In some cases, the brush head or neck vibration is greater than the vibration due to bristle movement. Users have reported discomfort from accidental contact with the brush neck or brush head when vibrating.

Additionally, it is known that when a user applies additional force to a power toothbrush, the bristle motion will tilt downward from the original motion pattern. In some cases, the bristles collapse under load, significantly reducing bristle movement.

To synchronize the vibration of the brush head with the rotation of the bristles and eliminate unwanted vibrations in the hard plastic of the brush head, neck, or handle, electric toothbrushes have been mounted on movable bristle holders on the brush head. , containing several brush tufts. Each bristle tuft includes several bristles, and the bristle tuft and corresponding bristle may be disposed at a perpendicular or non-perpendicular angle to the mounting surface of the brush head (herein " Also called "straight tufts" and "straight bristles" or "angled tufts" and "angled bristles"). The tresses may be arranged at any suitable angle, and some tresses may be arranged at a different angle than other tresses. Additionally, the tufts may be slanted up and down with respect to a line normal to the mounting surface, angled left and right with respect to a line normal to the mounting surface, or angled with respect to a line normal to the mounting surface. It may be angled in any combination of up/down and left/right.

Additionally, the electric toothbrush includes a motor, such as a linear motor, and a gear structure coupled to the motor that rotates the bristle tufts as the motor moves. The tress is rotated back and forth at a predetermined rotation angle (e.g., 28°, 33°, 45°, etc.) and at a specific rotation frequency exceeding a threshold frequency (e.g., 100 Hz, 115 Hz, 130 Hz, 145 Hz, etc.). . In some implementations, one rotation cycle, or period, is from the first half of the predetermined rotation angle (eg, 14°, 16°, 22°) to the second half of the predetermined rotation angle during the first time interval. (eg, −14°, −16°, −22°, etc.), and during the second time interval the first half of the predetermined rotation angle (eg, 14°, 16°, 22°). In other words, the time period corresponding to the rotation frequency includes a combination of the first time interval and the second time interval. Also, in some implementations, the tress may be rotated at a particular rotation frequency that is within a threshold frequency range (eg, 100 Hz to 200 Hz, 100 Hz to 150 Hz, etc.).

When the angled tufts rotate according to the motion of the linear motor, and when the bristles contact a contact surface such as a user's tooth surface, the motion bends/buckles the bristles, pushing the brush head toward the contact surface. and away from the contact surface, resulting in micro-oscillations (also referred to herein as "bristle drive pulsations"). Microvibration amplitude increases when a force that is greater than or equal to a threshold force (eg, 0.8 N) is applied to the contact surface. Furthermore, the micro-vibration frequency is synchronized with the frequency of rotation of the tuft. This provides the user with a smoother brushing experience and reduces the noise level of the electric toothbrush during brushing. Additionally, the micro-vibration amplitudes are generated in and through the bristles, rather than being generated in the handle, and are transmitted through the hard plastic back of the brush head and the brush neck. In this way, potentially objectionable vibrations are reduced through the hard plastic when the user experiences accidental contact with the hard plastic.

Furthermore, when additional loads are applied to the contact surface, the movement of the bristles remains stable and the bristles continue to rotate through the predetermined rotation angle. Furthermore, users who tested the electric toothbrush reported an enhanced experience when brushing with microvibrations.

In one embodiment, a power toothbrush includes a brush head including a plurality of bristles attached to the brush head at a non-perpendicular angle to the brush head. The power toothbrush also includes a power toothbrush handle removably attached to the brush head. A power toothbrush handle drives a plurality of bristles attached to a brush head to rotate clockwise and counterclockwise relative to the brush head about a rotational axis perpendicular to the mounting surface of the brush head at a frequency of rotation greater than or equal to a frequency threshold. It includes a motor configured to rotate counterclockwise. The brush head moves toward and away from the contact surface in synchronism with the rotation of the bristles.

In another embodiment, a power toothbrush includes a brush head including a plurality of bristles attached to the brush head. The power toothbrush also includes a power toothbrush handle removably attached to the brush head. The electric toothbrush handle includes a motor configured to drive a gear structure coupled to the motor, the gear structure converting movement of the motor into rotation of a plurality of bristles attached to the brush head. , is configured to rotate clockwise and counterclockwise relative to the brush head at a predetermined rotational frequency to move the brush head toward and away from the contact surface via pulsation of the bristle drive. ing.

In yet another embodiment, a power toothbrush includes a brush head that includes a plurality of bristles attached to the brush head at a non-perpendicular angle relative to the brush head. The power toothbrush also includes a power toothbrush handle removably attached to the brush head. A power toothbrush handle drives a plurality of bristles attached to a brush head to rotate clockwise and counterclockwise relative to the brush head at a rotational frequency greater than or equal to a frequency threshold to vibrate the brush head. Includes configured motor. The amount of brushhead vibration increases when the load applied to the contact surface increases above a threshold amount.

In another embodiment, a power toothbrush includes a brush head that includes a plurality of bristles attached to the brush head at a non-perpendicular angle relative to the brush head. The power toothbrush also includes a power toothbrush handle removably attached to the brush head. A power toothbrush handle drives a plurality of bristles attached to a brush head to rotate clockwise and counterclockwise relative to the brush head at a rotational frequency greater than or equal to a frequency threshold to vibrate the brush head. Includes configured motor. The brushhead vibrates at one or more vibration frequencies corresponding to the rotation frequencies.

In yet another embodiment, a power toothbrush includes a brush head that includes a plurality of bristles attached to the brush head at a non-perpendicular angle relative to the brush head. The power toothbrush also includes a brush neck attached to the brush head and a power toothbrush handle removably attached to the brush neck. The electric toothbrush handle drives a plurality of bristles attached to the brush head to rotate clockwise and counterclockwise with respect to the brush head at a rotational frequency greater than or equal to the frequency threshold, and the plurality of bristles, the brush It includes a head and a motor configured to oscillate the brush neck. The amount of vibration in the plurality of bristles exceeds the amount of vibration in the brush head and the amount of vibration in the brush neck.

In another embodiment, a power toothbrush includes a brush head that includes a plurality of bristles attached to the brush head at a non-perpendicular angle relative to the brush head. The power toothbrush also includes a brush neck attached to the brush head and a power toothbrush handle removably attached to the brush neck. The electric toothbrush handle drives a plurality of bristles attached to the brush head to rotate clockwise and counterclockwise with respect to the brush head at a rotation frequency equal to or higher than the frequency threshold at a predetermined rotation angle, and the brush head a motor configured to vibrate the The amount of rotation of the bristles remains substantially the same as the load applied to the contact surface increases.

In yet another embodiment, a method of providing bristle drive pulsation for a power toothbrush includes causing a motor included in a power toothbrush handle to rotate a plurality of bristles included in a brush head to a gear structure above a frequency threshold. A plurality of bristles are attached to the brush head at a non-perpendicular angle to the brush head, including rotating the brush head clockwise and counterclockwise at a frequency. As the bristles rotate, the method includes moving the brush head toward and away from the contact surface in synchronism with the rotation of the bristles by a motor or gear arrangement. include.

The figures described below represent various aspects of the systems and methods disclosed herein. It is to be understood that each figure depicts an embodiment of a particular aspect of the disclosed systems and methods, and that each figure is intended to be consistent with possible embodiments thereof. Further, wherever possible, the following description refers to reference numerals contained in the following figures, in which features illustrated in multiple figures are designated using consistent reference numerals. ing.
1 illustrates an exemplary electric toothbrush with angled bristles; 2 illustrates an exemplary brush head that can operate within the power toothbrush of FIG. 1; 1 shows an exemplary cross-sectional view of the interior of a power toothbrush handle; FIG. FIG. 4 illustrates an exemplary cross-sectional view of the interior of a power toothbrush refill; 2 shows a table showing the micro-vibrations of the electric toothbrush of FIG. 1 with various brush head types during bristle rotation; FIG. 4 shows a graph showing an exemplary movement of the brush head when zero force is applied to the contact surface; FIG. FIG. 5 shows another graph showing exemplary movement of the brush head when varying amounts of force are applied to the contact surface; FIG. FIG. 5 shows yet another graph showing the amount of vibration of the brushhead when various amounts of force are applied to the contact surface; FIG. Fig. 2 shows a graph showing a Fourier transform analysis of the frequency components of brushhead vibration; FIG. 4 is a graph showing a Fourier transform analysis of frequency components of brush head vibration in an alternative electric toothbrush system; FIG. FIG. 4 shows a graph showing an exemplary movement of the brush head and bristle rotation for a first refill having a first refill design; FIG. FIG. 12 shows a graph showing an exemplary movement of the brush head and bristle rotation for a second refill having a second refill design; FIG. FIG. 13 shows a graph showing an exemplary movement of the brush head and bristle rotation for a third refill having a third refill design; FIG. FIG. 4 shows a graph showing exemplary rotation angles of bristles over time as various amounts of force are applied to the contact surface; FIG. FIG. 11 illustrates an alternative electric toothbrush system showing a graph showing exemplary angles of bristle rotation over time when varying amounts of force are applied to the contact surface; FIG.

While the following language sets forth a detailed description of a number of different embodiments, the legal scope of the specification is defined by the terms of the following claims of this patent and equivalents: It should be understood that This detailed description is to be construed as exemplary only and does not describe every possible embodiment, as it would be impractical to describe every possible embodiment. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, and such embodiments would still be covered by the claims. will be included within the scope of

Also, terms may be expressly specified herein using the sentence "As used in this patent, the term '__' is defined herein to mean..." or similar sentences. It is to be understood that there is no intention to limit, either explicitly or implicitly, the meaning of a term beyond its simple or ordinary meaning unless defined; It should not be construed as limiting the scope based on any statement made in any section of this patent (except for the scope language). To the extent any term appearing in a claim at the end of this patent is referred to in this patent in a manner consistent with a single meaning, it is merely understood so as not to confuse the reader. It is not intended, by implication or otherwise, to limit the term in the claims to its single meaning, but is done so only for purposes of ease. Finally, unless a claim element is defined by describing the word "means" and function without any structural recitation, the scope of any claimed element is , is not intended to be construed under the application of 35 U.S.C. 112, sixth paragraph.

FIG. 1 shows an exemplary electric toothbrush 100 with angled bristles. The power toothbrush 100 may include a power toothbrush handle 35 and a brush refill 92 removably attached to the power toothbrush handle 35 and including a brush head 90 attached to a brush neck 95 . Electric toothbrush 100 may include a motor 37 and an energy source 39 in electrical communication with motor 37 . A motor 37 is operatively connected to a movable bristle holder disposed on the brush head 90 for moving the bristle holder. More specifically, the bristle holder may be a disc included in the brush head 90, with each bristle tuft attached to the disc. As the disc rotates, each tuft rotates. In some embodiments, motor 37 is a linear motor and is operably coupled to the movable bristle holder via a gear arrangement described in more detail below with reference to FIG. The bristle holder may undergo motion that is rotational, oscillating, translating, vibrating, or a combination thereof. The motor 37 rotates the bristle holder at a predetermined rotation angle (e.g., 28°, 33°, 45°, etc.) and at a particular rotation frequency exceeding a threshold frequency (e.g., 100 Hz, 115 Hz, 130 Hz, 145 Hz, etc.). It may rotate/oscillate back and forth. For example, the motor 37 rotates the bristle holder clockwise through a predetermined angle of rotation during a first time interval over 100 cycles per second, and then rotates the bristle holder clockwise through a predetermined angle of rotation during a second time interval. may rotate the bristle holder counterclockwise. In some implementations, the bristle holder may be rotated at a particular rotational frequency that is within a threshold frequency range (eg, 100 Hz-200 Hz, 100 Hz-150 Hz, etc.).

A bristle bundle 10 is attached to the bristle holder and contains several bristles. As shown in FIG. 1, the bristle tufts 10 and at least some of the bristles are angled with respect to the mounting surface of the brush head 90 so that the bristle tufts 10 and the bristles are aligned with the brush. It is disposed at a non-perpendicular angle to the mounting surface of head 90 . This is described in more detail below with reference to FIG. The brush head 90 can be provided as a removable head so that when the bristles (or other components) of the bristle holder deteriorate, they can be removed and replaced. Examples of electric toothbrushes that may be used with the present invention, including examples of drive systems for operably coupling a motor to a bristle holder (or otherwise move a bristle holder or head), use with a bristle holder types of cleaning elements for , structures suitable for use with removable heads, movement of bristle holders, other structural components and features, and operating or functional features or characteristics of electric toothbrushes are covered in U.S. Patents Application Publication Nos. 2002/0129454, 2005/0000044, 2003/0101526, U.S. Patent Nos. 5,577,285, 5,311,633, 5,289,604, 5,974,615, 5,930,858, 5,943,723, U.S. Patent Application Publication Nos. 2003/0154567, 2003/0163881, 2005/0235439 , US Pat. It is disclosed in Patent No. 6,058,541 and US Patent Application No. 2005/008050.

Although the bristle tuft 10 and bristles are shown in FIG. 1 as being disposed at a non-perpendicular angle to the mounting surface of the brush head 90, this is merely an example for ease of illustration. It's nothing more than In other embodiments, the bristle tufts 10 and bristles are arranged at a perpendicular angle to the mounting surface of the brush head 90 .

In some embodiments, power toothbrush 100 may include one or more sensors that may be included within head 90, neck 95, or handle 35 of the power toothbrush. Sensors include optical sensors or imaging sensors such as cameras, electromagnetic field sensors such as hall sensors, capacitance sensors, resistance sensors, inductive sensors, humidity sensors, motion sensors such as multi-axis accelerometers, acceleration sensors or tilt sensors, and pressure sensors. , gas sensors, vibration sensors, temperature sensors, and the like. Electric toothbrush 100 also includes light emitting diodes (LEDs) disposed around the exterior of handle 35 or brush neck 95 that are configured to change color based on the force or pressure detected by the pressure sensor. OK. For example, when the electric toothbrush 100 is activated and the user begins brushing teeth, the LED may emit white light. When the user applies force above a first threshold force (eg, 0.8 N) to the tooth surface, the LED changes color and emits a green light to indicate that the user is brushing with the proper amount of force. You may issue Then, when the user begins to apply excess force by applying a force above a second threshold force (e.g., 2.5 N), the LED will change color again, indicating that the user has reached the optimal force range (e.g., 0.8 N to 2.5 N) may emit a red light or another colored light to indicate that an external force is being applied. A controller included in power toothbrush 100 may receive pressure or force data from a pressure sensor. The controller may compare the pressure data or force data to the first threshold force and the second threshold force and may provide control signals to the LEDs based on the comparison to emit a particular color.

In some embodiments, refills 92 are disposable, and some refills 92 may be attached to and removed from power toothbrush handle 35 . For example, a family of four may share the same power toothbrush handle 35, each person attaching their own refill 92 to the power toothbrush handle 35 during use. Additionally, the refill 92 may have a limited life and the user may replace the old refill with a new refill after a certain number of uses.

FIG. 2 shows an enlarged view of the brush head 90 of FIG. As noted above, the brush head 90 includes a mounting surface 202 having a movable bristle holder 206 disposed thereon. A bristle holder 206 is attached to the bristle tufts 10, 204 each containing several bristles. As shown in FIG. 2, the tufts 10, 204 may be disposed at various non-perpendicular angles with respect to the mounting surface 202. As shown in FIG. Additionally, the tufts 10, 204 may be slanted up and down with respect to a line perpendicular to the mounting surface 202, or angled left and right with respect to a line perpendicular to the mounting surface 202, or the tufts 10, 204 may may be angled in a combination of up and down and left and right with respect to a line perpendicular to the

A motor 37 is coupled to a gear structure coupled to the bristle holder 206 to rotate the bristle holder 206 at a predetermined rotational angle and a predetermined rotational frequency. Motor 37 may be a linear motor that drives a gear structure. As the linear motor 37 moves up and down, the gear structure converts the motion of the linear motor 37 into rotation of the bristles. More specifically, the linear motor 37 may provide linear oscillatory motion via a drive shaft coupled to the linear motor 37, the linear vibration being transmitted to the brush head 90 and driven by respective gear units to the drive shaft. to the oscillating rotation of the bristle holder 206 about an axis of rotation that may be essentially perpendicular to the longitudinal axis along which the bristles oscillate, or about an axis of rotation perpendicular to the mounting surface of the brush head 90. may be converted. The motor 37 causes the gear structure through a linear oscillatory motion to rotate the bristles at a specified rotational frequency (e.g. 145 Hz) above a threshold frequency (e.g. 100 Hz) clockwise and at a predetermined rotational angle (e.g. 28°). Rotate counterclockwise. As the bristles rotate, the motor 37 also oscillates the brush head 90 through a linear oscillatory motion, toward and away from the contact surface, such as the user's teeth, in synchronism with the rotation of the bristles. move.

The interior of electric toothbrush handle 35, including at least a portion of the motor 37 and gear structure, is shown in FIG. 3A. In some embodiments, the drive shaft may be included in a geared structure. As noted above, power toothbrush 100 includes power toothbrush handle 35 and removable refill 92 . A motor housing 302 is disposed within the handle 35 .

The linear motor 37 includes a motor housing 302, an armature 304 mounted for linear oscillation along its longitudinal direction (parallel to the longitudinal axis L) as indicated by double arrow A, a stator 306 and a double arrow A. and a secondary mass unit 308 mounted for linear vibration along the longitudinal direction, as shown at B. A Cartesian coordinate system is shown, in which the x-axis coincides with the longitudinal axis L and the y-axis is transversely perpendicular to the x-axis. The z-axis is towards and away from the contact surface.

Stator 306 comprises a coil core 312 that may be fixedly connected to motor housing 302 and a stator coil 314 wound around coil core 312 . Although FIG. 3A shows an E-shaped (i.e., three teeth) steel bar, this excludes that other steel bar designs may be used, such as a U-shaped (i.e., two teeth) steel bar. not something to do. The teeth of coil core 312 have end faces facing permanent magnet array 316 attached to central portion 318 of armature 304 . Linear motor 37 may comprise at least two electrical contacts for supplying current to stator coils 314 during operation. Coil core 312 may be made of a stack of isolated sheets such as ferromagnetic metal sheets (“soft iron”, eg Fe—Si based metals).

The armature 304 may also be made (at least partially) of a stack of isolated sheets such as ferromagnetic metal sheets (eg, Fe—Ni based metals). The armature 304 may be attached to the housing 302 by at least one armature-mounted spring assembly 320,322, and the secondary mass unit 308 may be attached to the motor housing 302 by at least one secondary mass-mounted spring assembly 324,326. may be attached. In the illustrated exemplary embodiment, armature 304 is attached to housing 302 by two armature-mounted spring assemblies 320 and 322, and secondary mass 328 is attached to two secondary mass-mounted spring assemblies 324 and 326. attached to the housing by In one embodiment, the armature-mounted spring assemblies 320 and 322 or the secondary mass-mounted spring assemblies 324 and 326 are each embodied as leaf springs that can extend stationary in a plane perpendicular to the longitudinal axis L. These leaf springs may have a spiral shape with a first fastening portion located on the outer side of the spring and a second fastening portion located in a more central region of the spring.

Each of the mounting spring assemblies 320, 322, 324, 326 has one end (i.e., having a first fastening portion) fixedly connected at or to the motor housing 302 and an armature 304 or secondary mass. It may be at the other end (ie, the second fastening portion) each fixedly connected to the unit 308 . Each of the spring assemblies 320, 322, 324, or 326 described above may be made of a single leaf spring or of stacks of (specifically identically shaped) leaf springs stacked in the x-direction. Each of the leaf springs may have a certain thickness in the x-direction to achieve the target spring constant. The thickness and number of leaf springs may be set to adjust the properties of the components of the linear motor 37, such as the resonant and anti-resonant (i.e., cancellation) frequencies (the anti-resonance, or cancellation frequencies, are the armature and (the frequency at which the secondary masses not only move essentially out of phase, but at essentially the same amplitude so that vibrations transmitted to the motor housing are minimized). A high spring constant can be achieved with a single thick leaf spring rather than a stack of two thin leaf springs, but a thicker leaf spring will have a different deflection curve than a stack of two thin leaf springs. It has been found that the latter has better fatigue resistance and thus can improve the long life behavior of the overall motor design. As two vibrating systems: a first system comprising armature 304 with respective armature mounted spring assemblies 320 and 322, and a secondary mass unit 308 and respective secondary mass mounted spring assemblies 324 and 326. The second system is tightly coupled and the resonant frequencies of the two systems are strongly dependent. In one embodiment, the armature 304 may have locking projections 342 and 344 extending in the x-direction and centrally disposed with respect to the longitudinal axis L. As shown in FIG. As shown in FIG. 3A for an exemplary embodiment of a linear motor according to the present disclosure, lower locking projection 342 may be fixedly connected with lower armature mounting spring assembly 322 . Additionally, the upper locking projection 344 may be fixedly connected to the upper armature mounting spring assembly 320 . Additionally, the upper locking projection 344 may establish a connection with the drive shaft 346 such that linear oscillation of the armature 304, indicated by double arrow A, is directed to the drive shaft 346 during motion and to the drive shaft 346. It is transmitted from the shaft 346 to the bristle holder 206 . The drive shaft 346 may be centrally disposed with respect to the longitudinal axis L.

In addition, secondary mass 328 has locking projections 348 and 350 extending in the x-direction (i.e., longitudinal direction) and centrally disposed along longitudinal axis L. good. Upper locking projection 350 may be fixedly connected to secondary mass mounting spring assembly 326 . Additionally, the lower locking projection 348 may be fixedly connected to the lower secondary mass mounting spring assembly 324 .

The entire assembly of armature 304 (together with respective armature mounting assemblies 320 and 322) and secondary mass unit 308 essentially form a two-mass system oscillator (where armature 304 is connected to drive shaft 346). can be connected to a more distant, at least partly spring-like, mounting, which will be driven in operation via the , assuming that they can cancel each other out completely). As will be described in more detail below, the secondary mass unit 308 is used to excite the counter-vibration to the armature vibration during operation. Therefore, on the one hand the vibrations transmitted to the motor housing 302 (and thus the handle 35 of the electric toothbrush 100 to which the linear motor 37 is attached) are reduced compared to designs without the secondary mass unit 308 and on the other hand the housing , at least partially cancel each other out due to the anti-phase vibration of the secondary mass unit 308 relative to the vibration of the armature 304 . To accomplish this, the change in vibration of the armature 304 (eg, due to the load applied by the linear motor 37) is adjusted so that the countervibration can reduce the vibration felt by a user holding the handle of the electrical device. , is rapidly transmitted to the secondary mass unit 308 .

The armature 304 has several parts: two ends 352 and 354, one middle part 318, and two middle parts 356 connecting one end of the middle part 318 with the respective end 352 or 354 respectively. and 358. That is, the lower intermediate portion 356 connects the lower end of the central portion 318 with the lower end portion 352 , and the upper intermediate portion 358 connects the upper end of the central portion 318 with the upper end portion 354 . The lower end 352 and the upper end 354 may be centrally disposed about the longitudinal axis L with a distance to the motor housing 302 , with the central portion 318 positioned at a very short distance to the motor housing 302 . be done. That is, central portion 318 is parallel to longitudinal axis L and extends along the longitudinal axis closer to motor housing 302 . Accordingly, central portion 318 is recessed toward one side of motor housing 302 such that more structural volume is available between central portion 318 and the opposite side of motor housing 302 . In contrast to other linear motor designs known in electric toothbrushes, where the stator is arranged around the armature, this particular design of the armature 304 is arranged on the opposite side of the motor housing, as described above. Allows the stator 306 to be positioned opposite the central portion 318 of the armature 304 . A permanent magnet assembly 316 is disposed on the side of the central portion 318 of the armature 304 that faces the tooth end face of the coil core 312 . The permanent magnets may be made of (sintered) FeNdB (neodymium-iron-boron) material.

Specifically, the air gap between the end faces of the coil core 312 and the permanent magnet array 316 may extend proximate to and substantially centrally relative to the longitudinal axis L, and this design provides more It can provide low tilting force and assists in using the mounting spring assembly as a bearing for the armature as well. This, on the one hand, results in a simpler motor design and thus a relatively low-cost linear motor, and on the other hand allows higher forces to be provided by the linear motor in a given structural volume. resulting in design options for

FIG. 3B shows an exemplary gear structure included in refill 92 to drive movement of bristle holder 206 . Drive shaft 346, shown in FIG. 3A and included in power toothbrush handle 35, is coupled to refill portion 92 and oscillates linearly. The drive shaft 346 extends within the hollow of a generally tubular front housing 349 within the electric toothbrush handle 35 terminating in a connection 351 that makes a specific mechanical connection with the respective connector structure at the attachment. A connector structure suitable for establishing may be provided. Drive shaft 346 houses at its free end (opposite the end coupled to armature 304) a magnetic coupling element 355 for establishing a magnetic connection with the respective magnetic coupling element of mounting element 366. The drive shaft 346 has a holder portion 353 to obtain, so that the drive shaft 346 can transmit the linear motion provided by the armature 304 to the bristle holder 370 attached to the refill 92 for drive motion. Linear motion is provided by respective gear units within the refill 92 about an axis of rotation which may be essentially perpendicular to the longitudinal axis along which the drive shaft oscillates or perpendicular to the mounting surface of the brush head 90. may be translated into an oscillating rotation of the bristle holder 206 about an axis of rotation.

Referring to FIG. 3B, refill 92 includes a gear structure coupled to drive shaft 346 that is coupled to linear motor 37, the gear structure including drive member 364 having proximal end 364A and distal end 364B. The proximal end 364A may comprise a first attachment element 366 and the distal end 364B may comprise a connection 368. As shown in FIG. Connection 368 may be coupled to a bristle holder (eg, 370). The bristle holder 370 may be rotatably coupled to the mounting housing 372 such that the bristle holder 370 may move in an oscillating rotational manner when actuated. As shown in FIG. 3B, when connected, the outer surface of electric toothbrush handle 35 and the inner surface of refill 92 are in intimate contact, creating contact zone 380 . A press fit may be used to avoid gaps, and with an interference fit, the diameter between the parts may be 0.04 mm to 0.16 mm. This tight fit, or lack of clearance, between the connecting portion 351 of the electric toothbrush handle 35 and the mounting element of the refill 92 creates a lateral stiffness that prevents side-to-side movement of the refill 92 . In this way, the bending and buckling forces that occur in the bristles as they move in contact with a contact surface, such as the surface of a user's teeth, are toward and away from the contact surface rather than side to side. Induces movement within the bristle holder 370 in a direction.

The first mounting element 366 may comprise a permanent magnet or magnetizable element, such as a magnetizable block of iron or steel. Austenitic steels are typically not magnetizable, whereas martensitic or ferritic steels are typically magnetizable. The first mounting element 366 may be disposed within a recess in the proximal end 364A of the drive member 364. As shown in FIG.

As shown, drive member 364 may reciprocate generally parallel to longitudinal axis L 2 , as indicated by arrow 374 . Because connection 368 is eccentric to pivot axis 376, reciprocating motion of drive member 364 causes bristle holder 370 to rotate about the axis of rotation.

Drive member 364 may be relatively thin, allowing for a compact fit within refill 92 . Additionally, the drive member 364 may be mechanically stable and capable of transmitting a force of approximately 10N. Accordingly, the drive member 364 may have a natural frequency of at least 200 Hz, greater than about 225 Hz, greater than about 250 Hz, greater than about 275 Hz, or any number or range including or within the given value. may have

Drive member 364 may comprise any suitable material. Some examples include polyoxymethylene (POM), polyamide (PA), or polybutylene terephthalate (PBT). In some embodiments, additional reinforcement may be added to drive member 364 . For example, reinforcing fibers, such as Kevlar™ fibers, may be added to the material of the drive member 364 . Any other suitable reinforcing fibers may be added. Additionally, the drive member 364 may comprise a shape configured to reduce the likelihood of buckling. For example, drive member 364 may have a cross-section that is cruciform, Y-shaped, or any other suitable shape.

As previously mentioned, in some embodiments, power toothbrush 100 may have an operating frequency greater than about 120 Hz. At such frequencies, it is important in some embodiments that the refill 92 have a resonant frequency greater than that of the operating frequency. If the resonant frequency of refill 92 is too close to the desired frequency, resonant motion may be induced within refill 92 during operation. For example, refill 92 or drive member 364 may experience side-to-side movement. This side-to-side movement can be uncomfortable for the user and/or can create additional noise during operation. For those embodiments in which resonant motion is not desired, the resonant frequency of refill 92 may be greater than about 125 percent of the desired frequency.

The linear oscillatory motion A rotates the bristle holder 206 in a gear arrangement coupled to the motor 37 . In some implementations, the frequency of rotation of the bristle holder 206 is proportional to the frequency of the linear oscillatory motion A. Furthermore, the rotation amplitude or the predetermined rotation angle is proportional to the amplitude of the oscillatory motion A.

In addition to rotating the bristle holder 206 into the gear structure contained in the refill 92 that has a press fit with the electric toothbrush handle 35 less than the threshold distance, when in contact with a contact surface such as a user's tooth surface, the motor's The linear oscillatory motion M, the gear structure including the tight fit or lateral stiffness of the refill 92 to the electronic toothbrush handle 35, and/or the bending and buckling forces of the bristles that occur as the bristles move, are controlled by the brush head 90. periodically moved slightly toward and away from the contact surface (also called the z-direction) (e.g., the momentum in the direction of the contact surface may be less than 300 μm, such as between 100 μm and 300 μm ), this movement may be referred to as vibration or micro-vibration. In some embodiments, the micro-vibrations are caused by bristle properties such as bristle density, the angle at which the bristles are disposed in the bristle holder 206, and the stiffness of the bristle fibers, which creates bending and buckling forces. you can FIG. 4 shows exemplary movements of the brush head 90 as the bristles are rotated relative to three different brush heads 90 . Each brush head 90 may include a different brush head design, the bristle tufts 10 being angled at different angles, and the brush heads 90 including different bristle densities. For example, the bristle tufts 10 in the first brush head (brush head A) may be angled and may have a bristle density of approximately 3740 bristles. The bristle tufts 10 in the second brush head (brush head B) may be straight and have a higher bristle density of approximately 4000 bristles. The tufts 10 in the third brush head (brush head C) may be angled and have a lower bristle density of about 2460 bristles.

As shown in table 400, when the bristles rotate to the left, bristles B and brush head C move toward and away from the contact surface with a smaller amplitude (eg, 50 μm) than brush head A. move. As the bristles rotate to the left, brush head A moves toward and away from the contact surface with a greater amplitude than brush heads B and C (eg, 150 μm). When the bristles rotate to the right, the brush head B moves towards and away from the contact surface, again with a smaller amplitude (eg 50 μm). Thus, the brush head B oscillates twice during one rotation cycle of the bristles. This is further illustrated in FIG. 8B, described in more detail below. When the bristles rotate to the left, the brush head C moves only towards and away from the contact surface. This is further illustrated in FIG. 8C, described in more detail below. Additionally, when the bristles rotate to the right, brush head A does not move during the first part of the rotation. Brushhead A then moves toward and away from the contact surface with a smaller amplitude (eg, 50 μm) during the second portion of the rotation to the right. This is further illustrated in FIG. 8A, described in more detail below.

5A and 5B illustrate movement of the brush head 90 as various amounts of force are applied from the brush head 90 to the contact surface. This movement occurs while the motor 37 is running and the bristles are rotating. This movement is illustrated in the z-direction, which is movement of the brush head 90 toward and away from the contact surface, and in the y-direction, which is movement of the brush head 90 from side to side. The x direction is the up and down movement of the brush head 90 . In any case, graph 500 of FIG. 5A shows movement of brush head 90 when zero force is applied from brush head 90 to the contact surface (e.g., power toothbrush 100 is not yet in contact with the user's teeth). indicates In this scenario, the brush head 90 moves very little, appearing to move more in the y-direction than in the z-direction, yet there is still very little movement in the y-direction (eg, less than 100 μm). Graph 550 of FIG. 5B shows that when the brush head 90 applies zero force to the contact surface, when the brush head 90 applies a 1 N force to the contact surface, and when the brush head 90 applies a 2 N force to the contact surface. A comparative analysis of the motion of the brush head 90 when the brush head 90 is applied and when a 3N force is applied from the brush head 90 to the contact surface. When zero force is applied from the brushhead 90 to the contact surface, there is little movement in the z-direction, but when 1N, 2N, and 3N forces are applied, the brushhead 90 moves significantly more in the z-direction. exhibit a lot of movement. In each example, the brush head 90 moves about 200-300 μm in the z-direction. Additionally, the motion in the y-direction when 1N, 2N, and 3N forces are applied is approximately the same as when zero force is applied.

This is illustrated more clearly in FIG. 6, which shows a graph 600 showing the amount of vibration transmitted through the bristles of the brush head 90 when various amounts of force are applied to the contact surface. Graph 600 shows the amount of vibration as a function of the force applied to the contact surface, where the amount of vibration is measured as the standard deviation of the force measured for each applied load. The standard deviation of the applied force indicates the amplitude of the vibration force or bristle contact force in the z direction of the brush head 90 . This is because when the bending/buckling force of the bristles increases, the brush head 90 moves up and away from the contact surface, and when the bending/buckling force decreases, the brush head 90 moves toward the contact surface. to return to the bottom. In either case, as shown in graph 600, the amount of vibration is between 0.1N and 0.15N when the force applied to the contact surface is less than 1N. When the force applied to the contact surface increases above a threshold amount (for example, 0.8 N or more), the vibration amount increases significantly from 0.35 N to 0.45 N, and the vibration amount when the load is less than 1 N. The amount of vibration is three times that of .

Furthermore, the oscillation of the brush head 90, i.e., the periodic movement toward and away from the contact surface, causes the bristles to rotate, because the brush head 90 vibrates at a vibration frequency corresponding to the rotation frequency. can be synchronized with More specifically, the vibrational frequency component of the brush head 90 may include a fundamental frequency as the rotational frequency of the bristles and/or multiples of the rotational frequency such that the vibrational frequency matches the rotational frequency. As a result, the amount of noise generated by power toothbrush 100 during brushing is reduced compared to alternative systems that do not exhibit these harmonic effects. This also provides the user with a smoother sound and a smoother brushing experience.

FIG. 7A shows a graph 700 showing frequency components of vibration of the brush head 90 during tooth brushing when an amount of force (eg, 2N) is applied to the contact surface that exceeds a threshold amount of force. The frequency content is determined from a Fourier transform analysis, such as a Fast Fourier Transform (FFT), of the vibrations transmitted through the bristles of the brush head 90 . The rotation frequency of the bristles is 145 Hz. As shown in graph 700, the peak frequencies are 147 Hz, 293 Hz, and 437 Hz, which are substantially the same as the rotation frequency, twice the rotation frequency, and three times the rotation frequency, respectively. Therefore, the vibration of the brush head 90 is synchronized with the rotation of the bristles, and the rotation frequency and the vibration frequency are in harmony with each other.

In contrast, alternative power toothbrushes that include handle-driven pulsation do not exhibit similar harmonic effects as shown in graph 750 of FIG. 7B. Instead, the frequency content of the alternative electric toothbrush's vibrations appears to include multiple fundamental frequencies and mixtures of these fundamental frequencies, resulting in a louder, harsher toothbrush. More specifically, as shown in graph 750, the peak frequencies have a first fundamental frequency of 93 Hz, which is substantially the same as the rotation frequency, and a first fundamental frequency of 417 Hz, which is substantially the same as the pulsation frequency of the alternative electric toothbrush. and a second fundamental frequency. The peak frequencies also include 184 Hz, which is approximately twice the first fundamental frequency, 233 Hz, which is the difference between the second fundamental frequency and twice the first fundamental frequency, and approximately three times the first fundamental frequency. 327 Hz approximately equal to the difference between the second fundamental frequency and the first fundamental frequency; 367 Hz approximately four times the first fundamental frequency; 460 Hz approximately five times the first fundamental frequency; and 510 Hz, which is the sum of the first fundamental frequency and the second fundamental frequency.

8A-8C show further examples of synchronizing the oscillation of the brush head 90 and the rotation of the bristles of three different refills 92. FIG. Each refill 92 may include a refill design in which the tufts 10 are angled at different angles, and may include different tuft sizes, bristle densities, and bristle counts, which determine the micro-vibration amplitude and Affects frequency. For example, a first refill tuft 10 may be angled at 16°, a second refill tuft 10 may be perpendicular to the brush head, and a third refill tuft 10 may be , may be angled at 16° and may have a significantly lower bristle density than the first refill.

Each of the graphs 800, 830, 860 includes a comparison of bristle rotational motion and brush head movement as a function of time. In each graph 800, 830, 860 both the bristles and the brush head 90 exhibit sinusoidal motion patterns. Additionally, the vibration and rotation frequencies appear to be the same or multiples of each other. For example, in graph 800, the duration of each cycle of vibration and rotation appears to be approximately 7 ms, indicating vibration and rotation frequencies of approximately 145 Hz. In graph 830, the period of oscillation appears to be about half as long as the period of rotation, indicating a rotation frequency of about 145 Hz and an oscillation frequency of about 290 Hz. Similar to graph 800, in graph 860 both periods of oscillation and rotation appear approximately every 7 ms, indicating an oscillation and rotation frequency of approximately 145 Hz.

Additionally, in each graph 800, 830, 860, the period and amplitude of oscillation and rotation remain consistent over time. For example, in graph 800, each period of oscillation is approximately 7 ms and each period of rotation is approximately 7 ms. Further, in graph 800, each amplitude of oscillation is approximately 0.15 mm and each amplitude of rotation is approximately 1.5 mm. Amplitude and duration do not change over time. This is unlike alternative electric toothbrushes where the duration and amplitude of oscillations are inconsistent and can vary significantly over time or when different toothbrushing loads are applied.

Further, during brushing, the motor 37 causes the bristle holder 206 to maintain a consistent rotation angle that matches the predetermined rotation angle regardless of the amount of load or force applied to the contact surfaces. This is illustrated in FIG. 9A, which shows a graph 1000 showing exemplary rotation angles of the bristles over time as various amounts of force are applied to the contact surface. In graph 1000, the rotation angle is approximately 33° when 0 N is applied to the contact surface. Similarly, the angle of rotation when 1N, 2N, or 3N is applied to the contact surface is also about 33°, or such as between 31° and 35°. Therefore, the amount of rotation of the bristles remains substantially the same as the load applied to the contact surface increases. The angle of rotation of the bristle holder 206 does not decrease under load as in alternative power toothbrush systems, and greater loads may cause the bristles to collapse and/or the applied load may cause the motor/gear system to lose its effectiveness. Due to the reduced movement it results in a smaller rotation angle.

In contrast, as shown in graph 1050 of FIG. 9B, the alternative power toothbrush system has a rotation angle of about 46° when 0 N is applied to the contact surface. However, when 2N is applied to the contact surface, the rotation angle decreases to approximately 36°, and when 3N is applied to the contact surface, the rotation angle further decreases to approximately 32°. Thus, in the alternative power toothbrush system of Figure 9B, the applied load reduces the effective movement of the motor/gear system.

Throughout this specification, multiple instances may implement a component, act, or structure that is described in a single instance. Although individual acts of one or more methods are illustrated and described as separate acts, one or more of the individual acts may be performed simultaneously, and it is not necessary that the acts be performed in the order shown. no. Structures and functions presented as separate components in exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may also be implemented as separate components. These and other variations, modifications, additions, and improvements are also included within the scope of the subject matter herein.

Further, certain embodiments are described herein as comprising logic or several routines, subroutines, applications, or instructions. These may form either software (eg, code embodied on a machine-readable medium or in a transmitted signal) or hardware. In hardware, such as routines, are tangible units capable of performing particular operations, and may be configured or arranged in a particular manner. In exemplary embodiments, one or more computer systems (e.g., stand-alone, client or server computer systems) or one or more hardware modules of a computer system (e.g., a processor or group of processors) are described herein. It may be configured by software (eg, an application or application portion) as a hardware module that operates to perform the specified operations as described.

In various embodiments, hardware modules may be implemented mechanically or electronically. For example, a hardware module may include permanently configured dedicated circuitry or logic (eg, as a dedicated processor such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC)). A hardware module may also include programmable logic or circuitry (eg, contained within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform specified operations. The decision to implement a hardware module mechanically, in a dedicated and permanently configured circuit, or in a temporarily configured circuit (e.g., configured by software) is a cost and It will be appreciated that this may be determined by time considerations.

Thus, the term "hardware module" may be an entity that is physically constructed to operate in a particular manner or to perform specific operations described herein, even if it is permanently It should be understood to encompass tangible entities, whether configured (eg, wired) or temporarily configured (eg, programmed). Given embodiments in which the hardware modules are temporarily configured (eg, programmed), each of the hardware modules need not be configured or implemented at any point in time. For example, if the hardware modules include general-purpose processors configured using software, the general-purpose processors may be configured as different hardware modules at different times. Thus, software may configure a processor to form a particular hardware module at one time, and a different hardware module at a different time, for example.

Hardware modules can provide information to and receive information from other hardware modules. As such, the described hardware modules may be considered communicatively coupled. When multiple such hardware modules exist simultaneously, communication may be accomplished through signal transmissions connecting the hardware modules (eg, via appropriate circuits and buses). In embodiments in which multiple hardware modules are configured or instantiated at different times, communication between such hardware modules is, for example, through storage and retrieval of information in memory structures accessed by the multiple hardware modules. may be achieved. For example, one hardware module may perform an operation and store the output of that operation in a memory device to which the hardware module is communicatively coupled. Additional hardware modules can then later access the memory device to retrieve and process the stored output. A hardware module can also initiate communication with input or output devices and can operate on resources (eg, collections of information).

Various operations of the example methods described herein may be performed, at least in part, by one that is temporarily configured (e.g., by software) or permanently configured to perform the associated operations. It may be implemented by any of the above processors. Whether configured temporarily or permanently, such processors may form processor-implemented modules that operate to perform one or more operations or functions. Modules referred to herein may include processor-implemented modules in some exemplary embodiments.

Similarly, the methods or routines described herein may be at least partially processor-implemented. For example, at least some of the acts of a method may be performed by one or more processors or processor-implemented hardware modules. The specific capabilities of those operations may be distributed across one or more processors and may reside within a single machine as well as spread across multiple machines. In some exemplary embodiments, the processors may be located in a single location (eg, in a home environment, office environment, or as a server farm); may be distributed over any location.

The specific capabilities of those operations may be distributed across one or more processors and may reside within a single machine as well as spread across multiple machines. In some exemplary embodiments, one or more processors or processor-implemented modules may be located in a single geographic location (eg, in a home environment, office environment, or server farm). In other exemplary embodiments, one or more processors or processor-implemented modules may be distributed across multiple geographic locations.

Unless otherwise specified, descriptions herein using words such as "process", "calculate", "compute", "determine", "present", "display" may refer to one or more memory (e.g., volatile memory, nonvolatile memory, or combinations thereof), registers, or other machine components that receive, store, transmit, or display information. , or optical) to any machine (eg, computer) action or process that manipulates or transforms data represented as quantities.

References to "one embodiment" or "an embodiment" throughout this specification mean that a particular feature, structure, or characteristic described in connection with this embodiment Meant to be included in at least one embodiment of the present invention. Thus, the appearances of the phrase "in one embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

Some embodiments may be described using the terms "coupled" and "connected" along with their derivatives. For example, some embodiments may be described using the term "coupled" to indicate that two or more elements are in direct physical or electrical contact. However, the term "coupled" can also mean that two or more elements are not in direct contact with each other, but still cooperate or interact with each other. Embodiments are not limited to this situation.

As used herein, "comprises", "comprising", "includes", "including", "has", "having The term having" or any other variation thereof is intended to correspond to non-exclusive inclusion. For example, a process, method, article, or apparatus, including a listing of elements, is not necessarily limited to only those elements, not explicitly listed or such processes, methods, articles, or It may contain other elements specific to the device. Further, unless expressly stated to the contrary, "or" refers to an inclusive "or" and to an exclusive "or". It does not refer to "or". For example, the condition A or B is that A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists) and both A and B are true (or exist).

Additionally, use of the "a" or "an" are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the description. This specification and the claims below should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

In the context of the present disclosure, the term "substantially" means an element or mechanism that, in theory, would be expected to exhibit an exact match or behavior, but which in practice may be embodied as being slightly less exact. means the configuration of As such, the term means that a quantitative value, measurement, or other relevant expression can be obtained from a stated standard without altering the basic function of the object in question. It indicates the degree of variability.

The dimensions and values disclosed herein should not be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range enclosing that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

The disclosure of all documents cited herein, including any cross-references or related patents or applications, is hereby incorporated by reference in its entirety unless expressly excluded or otherwise limited. be Citation of any document is not considered prior art to any invention disclosed or claimed herein, or taken alone or in combination with any other reference(s) Any such invention is not considered to teach, suggest or disclose at times. Further, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition given to that term in this document shall control. shall be

This detailed description is to be construed as exemplary only, and since it is impractical, if not impossible, to describe all possible embodiments, all possible embodiments does not explain Numerous alternative embodiments may be implemented, using either current technology or technology developed after the filing date of this application.

Claims (11)

an electric toothbrush,
a brush head including a plurality of bristles mounted on a bristle holder mounting surface of the brush head at a non-perpendicular angle to the brush head;
a brush removably attached to the brush head and configured to drive the plurality of bristles attached to the brush head rotatable about an axis of rotation perpendicular to the mounting surface of the brush head ; A handle including a near motor, wherein the plurality of bristles are rotatable clockwise and counterclockwise relative to the brush head at at least one rotational frequency, the at least one rotational frequency comprising: a handle that is greater than or equal to a frequency threshold;
The brush head is synchronized with the rotation of the plurality of bristles by vibrating at one or more vibration frequencies corresponding to the predetermined rotation frequency during movement of the bristles in contact with the contact surface. , arranged to move toward and away from the contact surface;
The one or more vibration frequencies include a fundamental frequency that is the rotational frequency of the plurality of bristles and/or multiples of the fundamental frequency,
The linear motor includes a motor housing, an armature mounted for linear oscillation along a longitudinal direction, a stator, a secondary mass unit mounted for linear oscillation along the longitudinal direction, has
An electric toothbrush, wherein the linear motor is arranged to provide linear oscillatory motion via a drive shaft coupled to the linear motor, the linear motion being transmitted to the brush head. The properties of the bristles include bristle density, the angle at which the bristles are attached to the brush head, and the stiffness of the bristles, which provides bending and buckling forces. The electric toothbrush according to claim 1 , comprising at least one of: The linear motor is configured to rotate the plurality of bristles clockwise during a first time interval and counterclockwise during a second time interval; 3. The electric toothbrush according to claim 1 or 2 , wherein the period corresponding to frequency comprises a combination of said first time interval and said second time interval. The electric toothbrush according to any one of claims 1-3 , wherein the plurality of bristles are attached to the brush head at a non-perpendicular angle relative to the brush head. The electric toothbrush according to any one of claims 1 to 4 , wherein the brush head moves toward and away from the contact surface by an amount corresponding to the standard deviation of the bristle contact force. The vibration amplitude of the brush head increases as the load applied to the contact surface increases above a threshold amount, specifically the threshold is between 0.8N and 1.0N, wherein the threshold is 0.8N to 1.0N . 6. The electric toothbrush according to any one of 5 . A refill including the brush head and the brush neck, the refill being removably attached to the electric toothbrush handle, wherein when the refill is attached to the electric toothbrush handle, an inner surface of the refill and the electric power An electric toothbrush according to any preceding claim, wherein the distance between the outer surface of the toothbrush handle is less than 0.16 mm. The linear motor is configured to rotate the plurality of bristles clockwise and counterclockwise by a predetermined rotation angle, and the predetermined rotation frequency is higher than 100 Hz . or the electric toothbrush according to item 1. 9. The handle of any preceding claim, further comprising a light source and a pressure sensor, the light source configured to change color in response to changes in pressure detected by the pressure sensor. or the electric toothbrush according to item 1. The brush bristle characteristics are set such that the vibration amount is approximately tripled from the vibration amount below the first applied force threshold to the vibration amount above the first applied force threshold, specifically: The vibration amount expressed as the standard deviation of the applied force is 0.1N to 0.15N below the first threshold, and the vibration amount above the first threshold is 0.35N to 0.45N. , wherein the first threshold is 0.8N or higher . A method for providing bristle-driven pulsation of an electric toothbrush, comprising:
A motor contained in an electric toothbrush handle causes a gear structure to rotate a plurality of bristles contained in a brush head clockwise and counterclockwise with respect to said brush head at a rotational frequency equal to or greater than a frequency threshold. and said plurality of bristles are attached to said brush head at a non-perpendicular angle to said brush head;
When the plurality of brush bristles rotate, the motor and the gear structure vibrate at one or more vibration frequencies corresponding to the predetermined rotation frequency, thereby rotating the plurality of brush bristles. synchronously moving the brush head toward and away from the contact surface;
The method, wherein the one or more vibrational frequencies include a fundamental frequency and/or multiples of the fundamental frequency that is the rotational frequency of the plurality of bristles.

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